Mining apparatus

ABSTRACT

A temporary roof support apparatus attachable to mining roof drilling and bolting machines advances a boom with a pivotally moveable extendible column at the boom end into unsupported roof areas in a mine room, pivots the columns into vertical disposition, extends them into load bearing compression between the mine room roof and floor and temporarily supports the roof against cave-in while roof bolting proceeds.

United States Patent 1191 Fletcher MINING APPARATUS [75] Inventor: James Robert Fletcher, Huntington,

W. Va.

[73] Assignee: J. H. Fletcher & Co., Huntington,

W. Va.

[22] Filed: Dec. 22, 1972 211 Appl. No.: 317,769

[52] U.S. Cl. 248/354 H, 61/45 A [51] Int. Cl ..E21d 11/16 [58] Field of Search... 248/354 H, 357; 254/93 VA,

254/2 R, 2 B; 61/45 D; 52/118 [56] References Cited UNITED STATES PATENTS 2,826,898 3/1958 Joy 61/45 D 2,857,125 10/1958 Mills et al. 248/354 H FOREIGN PATENTS OR APPLICATlONS 145,773 5/1951 Australia 61/45 D Aug. 26, 1.974

870,486 6/1961 Great Britain 61/45 D 865,922 4/1961 Great Britain 61/45 D 1,198,866 12/1959 France 61/45 D 968,668 9/1964 Great Britain 61/45 D 654,985 7/1951 Great Britain...., 61/45 D Primary Examiner-J. Franklin Foss Attorney, Agent, or Firm-Maurice W. Ryan, Esq.

[5 7] ABSTRACT A temporary roof support apparatus attachable to mining roof drilling and bolting machines advances a boom with a pivotally moveable extendible column at the 'boom end into unsupported roof areas in a mine room, pivots the columns into vertical disposition, extends them into load bearing compression between the mine room roof and floor and temporarily supports the roof against cave-in while roof bolting proceeds.

7 Claims, 1 Drawing Figure MINING APPARATUS This invention relates to mining apparatus and more particularly to a mining machine which provides a means of temporarily supporting the overhead or roof of a mine room or gallery from which detritus, coal for instance, has been removed, before and during the installation of a permanent roof supporting system such as an array of roof bolts.

In conventional mining practice the roofs of rooms from which detritus has been won are secured against collapse or roof falls by the installation of roof bolts. In present coal mining practice a machine known as a roof bolter is moved into the room on a self propelled tractor vehicle periodically as and after the coal extraction process has proceeded to a considered safe limit, the roof of the mined room is drilled and bolted and the roof bolter is removed to permit re-entry of the coal extraction crew with whatever apparatus they may use to perform the next coal removing sequence at the face where they left off but now under a roof which is safely supported right up to the working face of the vein being mined. Thus the normal procedure then is for the roof bolting crew to follow the coal extraction crew into the room being worked and to secure the roof continually as the mining proceeds so that the extraction crew personnel are not required to work undergreat expanses of unsupportedv roof. The laws governing mining impose justifiably strict safety standards in this regard. Where mechanized so-called continuous miners are used, as is quite common in present day coal mining, the continuous miner operator normally sits at machine controls about twenty feet rearward of the working face. Since safety requirements and sensible practice dictate that no one should be allowed to advance into mine areas of unsupported roof, the continuous miner operator customarily cuts into a fresh working face to a depth of about twenty feet, at which point he will be sitting just about under the lastto have been installed roof bolts, and, at which time he will back out with the continuous miner and make way for the roof bolting crew to come in and install roof bolts up to the just left off working face. While the safety requirements imposed by law and practiced by custom are quite well followed in respect of coal extraction crew personnel, continuous miner operators for instance, roof bolting crew personnel, without the advantages of the present invention, must of necessity advance into unsupported roof areas of the mine to perform the required roof drilling and roof bolt installation. This, it will be readily ap preciated, is not a safe or desireable situation, but the lack of technological advances, up to the time of the present invention, has left the goal of equating the safety of roof bolting crews to that of the extraction crews an unattained desideratum.

With this then being the state of the art, the present invention was conceived and developed with the principle objective of providing for the safe temporary support of mine roofs while roof bolting crews worked under them installing roof bolts to effect more permanent structural integrity and conditions afforded the extraction crews.

The present invention also provides a temporary roof supporting system which is remotely operable by personnel who may then remain completely'under fully bolted supported roof areas while performing temporary roof support operations in the advanced just mined areas of a mine.

A further feature of the invention is that it is readily adaptable to mounting on roof drilling and bolting machines conventionally used and thus does not require special or separate tractor means to bring it into the work site.

Certain embodiments of the invention also are readily disconnectable from each other so that the column means which effect the temporary roof support for instance may be disconnected from the boom ends and left in place to complete more advanced temporary roof support installations.

These and many other features and advantages of the invention will become the more readily apparent from the ensuing detailed description and the drawing which is perspective view showing apparatus according to present invention mounted on the front end of a tractor mechanism and in erect, roof supporting position.

In general, the present invention comprehends apparatus for effecting roof support in confined roofed spaces comprising, in combination, column means continuously extendible from a first length to a second length within a range of second lengths, boom means having a proximal end and a remote end, extending substantially horizontally from a boom anchor support affixed to said boom means at the proximal end thereof; pivot means connecting said column means pivotally to said boom means at the remote end thereof, adapted to permit pivotal movement of the column means in substantially coplanar orientation with the longitudinal axis of the boom means from a first position in which the column means is disposed towards the horizontal, towards and into a second position in which the column means is erect, substantially vertical, and substantially normal to the longitudinal axis of the boom means; first motive means to move the column means pivotally between and into its said first and said second positions; and second motive means to extend the column means from its first length to a second length, and to retract said column means from said second length towards its first length.

Apparatus according to the invention may advantageously include roof underspanning means mounted on the column means at the portion thereof which is uppermost when the column means is in its erect, substantially vertical position.

The roof underspanning means may to further advantage 'be pivotally mounted on the column means so as to be maintainable in a substantially horizontal disposition for all positions assumed by the column means.

It is also possible, and may be preferred in some cases in practicing the invention, that the pivot means connecting the column means to the boom means be a selectably detachable pivot means.

Alternative embodiments of apparatus according to the invention may advantageously include a boom means which is selectably extendible and retractable between its proximal end and its remote end.

Although other modes of motive means may be used in successfully practicing the invention, the preferred embodiments employ first motive means and second motive means which are hydraulically actuated.

With reference to the drawing, a temporary roof support apparatus according to the invention is shown generally at 11 attached to the front end of a roof drillingbolting machine 13, shown partially. The apparatus is shown attached to and supported by a bracket arrangement connecting the proximal end 17 of a boom 19 to the machine 13. Boom 19 extends cantilevered substantially horizontally from its proximal end 17 to its remote end 21 where a journal or pivot 23 connects a column 25 to the boom in a manner which permits pivotal movement of the column in a vertical plane, which also includes the longitudinal axis of the boom 19, from a first position in which the column 25 is disposed towards the horizontal from the position in which it is shown in the drawing, towards and into a second position in which it is erect, substantially vertical and substantially normal to the longitudinal axis of the boom 19. The drawing shows the column 25 in this second position. In its first position the column rests on an angle support 27 mounted atop the boom 19. This arrangement facilitates the motive means linkages inasmuch as it is not necessary to start pivotally raising the column from a totally flat horizontal disposition in its first position.

Column 25 includes two slidably nesting boxlike segments 25a and 25b, the moveable segment 25b nesting slidably in the fixed segment 25a. Fixed segment 25a is provided with a mounting bracket 29 which includes suitable flanges to accommodate the pivot 23 which effects column connection to the remote end 21 of the boom 19. A footplate 31 is provided at the lowermost end of segment 25a of column 25 and functions as a load distributor on the mine room floor 33 when the column is erect and bearing a roof load.

A hydraulic jack 35 is disposed interiorly of column 25 and is attached to the column segments 25a,25b, so as to extend the column from a first length in which segment 25b is substantially fully nested in segment 25a to a second length where roof support is effected.

Atop column 25 at the uppermost end of its segment 25b, a roof underspanning structure is pivotally mounted. As shown, the roof underspanning structure comprises a frame 37 attached to column 25 segment 25b by a pivot 43. The longitudinal axis of frame 37 extends coplanarlywith the longitudinal axes of the column 25 and the boom 19. Roof underspanning beams 39,41 are fixedly attached respectively to the aft and fore ends of the frame 37 and extend laterally of the longitudinal axis of the frame 37 so that the net effect is to form an H shaped roof underspanning structure which picks up roof load under a greater roof area than would otherwise be possible with just an unadorned column top and transmits that load to and through column 25 to footplate 31. Roof contact pads 45 are provided to facilitate roof surface contact and effect load distribution at the beams 39, 41 ends. The H shaped roof underspanning structure can swing pivotally in its entirety relative to the uppermost end of column 25 to which it is attached by the pivot 43, and thus assume a substantially horizontal disposition parallel to the mine roof surface irrespective of the tilt orientation of the column 25. It has been found advantageous in working embodiments of my invention to control the pivotal swing of the roof underspanning assembly relative to the column 25 by spring biasing it to fold down towards the column 25 with beam 41 down and beam 39 up so that when the column 25 is in its first position against the angle support 27, the roof underspanning assembly lies substantially flat and horizontal and well within the frontal silhouette of the tractor vehicle on which the invention may be mounted. A further advantage is provided by the inclusion of detents 47 which act to hold the roof underspanning structure in a horizontal disposition atop the column as the column is being raised into roof contacting position.

An alternative mode of affixing the beams 39, 41 to the frame 37 comprehends the employment of journals or pivots 49 which permit the pivotal movement of the beams 39, 41 in lateral vertical planes normal to the longitudinal axis of the apparatus to accommodate whatever roof slope differences and roof unevenness in operation. The pivots 49 may be coil spring or otherwise resiliently biased so that-in non-load bearing circumstances they will maintain a substantially horizontal non-tilted disposition. The contact pads 45 may also be adjustable relative to the beams mounting them to insure seating adequately against the roof undersurface. Thus the total capability of the H shaped roof underspanning structure enables. the roof to be contacted by the contact pads at multiple points of the mine roof which may be at multiply different elevations.

The actuating or motive means for the control of the movement of column 25 from and to and between its first and second positions is provided by a hydraulic system comprising a jack 49 connected between the underside of the column assembly, and hydraulic lines, valves, controls, gauges and other conventional componentry not shown since considered to be well within the knowledge of persons conversant with the mechanical arts.

The actuating or motive means for the extension of the column and its retraction similarly comprises, in addition to the jack 3S, hydraulic lines, valves, controls, gauges and other conventional componentry not shown for the purposes of simplifying the illustration of the more significant features of the invention.

To operate the apparatus of the invention, the operator-miner trams into position towards a fresh working face from which the extraction crew has just retreated, with the column 25 in its first position. The boom remote end 21 is located, from the operating station under a safely bolted roof, to the desired position and the hydraulic system operated to raise the column to its second position. In the course of the upswing of column 25, the H shaped roof underspanning assembly levels into horizontal disposition either by the beam 39 making initial roof contact and urging the assembly into a detent held position, or by suitable mechanical leveling arrangements, such as springs. The operator then actuates the hydraulic system to extend the column jack and bring the roof underspanning assembly contact pads into bearing on the roof with a force which may be preselected by means of a relief valve 51 for instance. By means of pressure indication at the control station, the operators know when the load is assumed and the hydraulic system pressure is halted and held by means of a check valve 53 in the system.

With the temporary roof support operation accomplished, the roof bolting operation proceeds under a safely supported roof.

At the completion of a roof bolting sequence, the procedure is reversed. The miner-operator lowers the column 25 to its retracted position, tilts it back against the angle support 27 on boom 19 and trams back out of the area to permit reentry of the extraction crew.

EXAMPLE A temporary roof support apparatus was attached to the front end of a dual boom roof bolter manufactured by the J. H. Fletcher & Co. of Huntington West Virginia. The invention was disposed midway between the two drilling-bolting booms of the machine. The column 25 was made up of a two-sleeve, double-acting hydraulic jack mounted in a two piece nesting square tube outer shell or sleeve comprising the column segments 25a and 25b. The boom 19 was connected to the lower column segment through another double acting hydraulic jack and motive power supplied from the dual boom driller-bolters hydraulic system. Additionally required controls were installed in the operating cockpit. This machine was tested in mining operations and achieved the expected completely satisfactory results.

Numerous alternative embodiments of apparatus within the scope and spirit of my invention will, in the light of the foregoing disclosure, occur to persons familiar with the art. It is therefore intended that the description herein be considered as illustrative only and not taken in any limiting sense.

What is claimed is:

1. Apparatus for effecting roof support in confined roofed spaces comprising, in combination,

a. column means continuously extendible from a first length to a second length within a range of second lengths;

b. boom means having a proximal end and a remote end, extending substantially horizontally from a boom anchor support affixed to said boom means at the proximal end thereof;

c. pivot means connecting said column means pivotally to said boom means at the remote end thereof, adapted to permit pivotal movement of the column means in substantially coplanar orientation with the longitudinal axis of the boom means from a first position in which the column means is disposed towards the horizontal, towards and into a second position in which the column means is erect, substantially vertical, and substantially normal to the longitudinal axis of the boom means;

(I. first motive means to move the column means pivotally between and into its said first and said second positions; and

e. second motive means to extend the column means from its first length to a second length, and to re tract said column means from said second length towards its first length.

2. Apparatus according to claim 1 in combination with roof underspanning means mounted on said column means at the portion thereof which is uppermost when said column means is in its erect, substantially vertical position 3. Apparatus according to claim 2 wherein said roof underspanning means is pivotally mounted on said column means so as to be maintainable in a substantially horizontal disposition for all positions assumed by said column means.

4. Apparatus according to claim 1 wherein the pivot means connecting the column means to the boom means is a selectably detachable pivot means.

5. Apparatus according to claim 1 wherein the boom means is selectably extendible and retractable between its proximal end and its remote end.

6. Apparatus according to claim 1 wherein said first motive means and said second motive means are hydraulically actuated.

7. Apparatus according to claim 1 wherein the boom means is cantilevered from the boom anchor support. 

1. Apparatus for effecting roof support in confined roofed spaces comprising, in combination, a. column means continuously extendible from a first length to a second length within a range of second lengths; b. boom means having a proximal end and a remote end, extending substantially horizontally from a boom anchor support affixed to said boom means at the proximal end thereof; c. pivot means connecting said column means pivotally to said boom means at the remote end thereof, adapted to permit pivotal movement of the column means in substantially coplanar orientation with the longitudinal axis of the boom means from a first position in which the column means is disposed towards the horizontal, towards and into a second position in which the column means is erect, substantially vertical, and substantially normal to the longitudinal axis of the boom means; d. first motive means to move the column means pivotally between and into its said first and said second positions; and e. second motive means to extend the column means from its first length to a second length, and to retract said column means from said second length towards its first length.
 2. Apparatus according to claim 1 in combination with roof underspanning means mounted on said column means at the portion thereof which is uppermost when said column means is in its erect, substantially vertical position
 3. Apparatus according to claim 2 wherein said roof underspanning means is pivotally mounted on said column means so as to be maintainable in a substantially horizontal disposition for all positions assumed by said column means.
 4. Apparatus according to claim 1 wherein the pivot means connecting the column means to the boom means is a selectably detachable pivot means.
 5. Apparatus according to claim 1 wherein the boom means is selectably extendible and retractable between its proximal end and its remote end.
 6. Apparatus according to claim 1 wherein said first motive means and said second motive means are hydraulically actuated.
 7. Apparatus according to claim 1 wherein the boom means is cantilevered from the boom anchor support. 